I propose to study the mechanism of synergistic hormone interaction by studying RNA synthesis and protein synthesis induced by steroid and terpenoid hormones. Changes in RNA synthesis will be assessed by determining the stimulation and/or suppression of RNA polymerases in silkmoth pupal wing tissue which has been treated with ecdysone and/or juvenile hormone. Both nucleolar and nucleoplasmic RNA polymerases will be studied. Specific protein synthesis will be studied at short time intervals after hormone (s) administration to learn about early biochemical events and at various times after the target tissue responds to the hormone (s) in order to study the effects of the hormone (s) on the developmental sequence of structural protein synthesis. The specificity and potency of several forms of steroid hormones will be determined in order to elucidate the most active hormone. In conjunction with these biochemical events, the binding of steroid and terpenoid hormones to hemolymph, and cytoplasmic and nuclear components of target tisues will be studied in an attempt to correlate binding events with biological responses. These studies will aid in our understanding of the mechanism of action of steroid and terpenoid hormones.